1. Technical Field
Various embodiments relate to a semiconductor device and an operating method thereof.
2. Related Art
A semiconductor memory device, in particular, a flash memory device, in which data written in a memory cell remains, rather than becoming extinct, although power is not supplied thereto, has continued to be increasingly used as a data storage medium. However, a flash memory device readily malfunctions due to a tendency that a threshold voltage distribution of a programming-completed cell is changed due to various factors caused during a program operation.
FIG. 1 is a view illustrating interference between bit lines made during a program operation. In FIG. 1, a portion of a memory cell array 100 of a general flash memory device is illustrated.
Referring to FIG. 1, first to sixth memory cells MC0˜MC5, respectively, are illustrated. The first to third memory cells MC0˜MC2, respectively, are connected to a word line WLn, and fourth to sixth memory cells MC3˜MC5, respectively, are connected to a word line WLn+1. The memory cells connected to the same word line constitute at least one page. For example, when each memory cell is a single level cell, the first to third memory cells MC0˜MC2 connected to the word line WLn and the fourth to six memory cells MC3˜MC5 connected to the word line WLn+1 constitute a single page, respectively.
A single page includes an even page and an odd page. The even page includes cells connected to even bit lines BLe. The odd page includes cells connected to odd bit lines BLo. Programming the cells connected to the even bit lines BLe is called even page programming, and programming cells connected to the odd bit lines BLo is called odd page programming. In programming the even page MC1 and the odd pages MC0 and MC2 connected to the same word line, e.g., programming is sequentially performed such that he word line WLn, the even page MC1 is programmed, and subsequently, the odd pages MC0 and MC2 are programmed, so a first programmed page is interfered by a program operation performed on a next page. As a result, a threshold voltage of the page, on which programming was first completed, namely, the even page MC1, may change. The change in the threshold voltage may cause neighboring threshold voltage distributions to overlap. This phenomenon increasingly occurs as the interval between adjacent cells narrows according to a reduction in a cell size of a flash memory device. Thus, a method capable of preventing a degradation of threshold voltage distribution characteristics due to interference between bit lines during a program operation of a flash memory device is required.